Cleaner separation of Verifier / Constraint Cheker duties (#188)

Author: JoshOrndorff

tuxedo-core/aggregator/src/lib.rs

@@ -101,11 +101,19 @@ pub fn tuxedo_verifier(_: TokenStream, body: TokenStream) -> TokenStream {
     let mut redeemer_type_name = outer_type.to_string();
     redeemer_type_name.push_str("Redeemer");
     let redeemer_type = Ident::new(&redeemer_type_name, outer_type.span());
+    let type_for_new_unspendable = inner_types
+        .clone()
+        .next()
+        .expect("At least one verifier variant expected.");
 
     // TODO there must be a better way to do this, right?
     let inner_types2 = inner_types.clone();
     let variants2 = variants.clone();
     let variants3 = variants.clone();
+    let variant_for_new_unspendable = variants
+        .clone()
+        .next()
+        .expect("At least one verifier variant expected.");
 
     let as_variants = variants.clone().map(|v| {
         let s = format!("as_{}", v);
@@ -160,6 +168,14 @@ pub fn tuxedo_verifier(_: TokenStream, body: TokenStream) -> TokenStream {
                     )*
                 }
             }
+
+            // The aggregation macro assumes that the first variant is able to produce a new unspendable instance.
+            // In the future this could be made nicer (but maybe not worth the complexity) by allowing an additional
+            // annotation to the one that can be used as unspendable eg `#[unspendable]`
+            // If this ever becomes a challenge just add an explicit `Unspendable` variant first.
+            fn new_unspendable() -> Option<Self> {
+                #type_for_new_unspendable::new_unspendable().map(|inner| Self::#variant_for_new_unspendable(inner))
+            }
         }
     };
     output.into()
@@ -173,9 +189,8 @@ pub fn tuxedo_verifier(_: TokenStream, body: TokenStream) -> TokenStream {
 /// just like this original enum. however, the contained values in the error enum are of the corresponding types
 /// for the inner constraint checker.
 #[proc_macro_attribute]
-pub fn tuxedo_constraint_checker(attrs: TokenStream, body: TokenStream) -> TokenStream {
+pub fn tuxedo_constraint_checker(_attrs: TokenStream, body: TokenStream) -> TokenStream {
     let ast = parse_macro_input!(body as ItemEnum);
-    let verifier = parse_macro_input!(attrs as Ident);
     let original_code = ast.clone();
 
     let outer_type = ast.ident;
@@ -204,23 +219,16 @@ pub fn tuxedo_constraint_checker(attrs: TokenStream, body: TokenStream) -> Token
     error_type_name.push_str("Error");
     let error_type = Ident::new(&error_type_name, outer_type.span());
 
-    let mut inherent_hooks_name = outer_type.to_string();
-    inherent_hooks_name.push_str("InherentHooks");
-    let inherent_hooks = Ident::new(&inherent_hooks_name, outer_type.span());
-
     let vis = ast.vis;
 
     // TODO there must be a better way to do this, right?
     let inner_types2 = inner_types.clone();
     let inner_types3 = inner_types.clone();
     let inner_types4 = inner_types.clone();
-    let inner_types6 = inner_types.clone();
-    let inner_types7 = inner_types.clone();
     let variants2 = variants.clone();
     let variants3 = variants.clone();
     let variants4 = variants.clone();
     let variants5 = variants.clone();
-    let variants6 = variants.clone();
 
     let output = quote! {
         // Preserve the original enum, and write the From impls
@@ -235,27 +243,39 @@ pub fn tuxedo_constraint_checker(attrs: TokenStream, body: TokenStream) -> Token
         #[derive(Debug)]
         #vis enum #error_type {
             #(
-                #variants(<#inner_types as tuxedo_core::ConstraintChecker<#verifier>>::Error),
+                #variants(<#inner_types as tuxedo_core::ConstraintChecker>::Error),
             )*
         }
 
-        /// This type is generated by the `#[tuxedo_constraint_checker]` macro.
-        /// It is a combined set of inherent hooks for the inherent hooks of each individual checker.
-        ///
-        /// This type is accessible downstream as `<OuterConstraintChecker as ConstraintChecker>::InherentHooks`
-        #[derive(Debug, scale_info::TypeInfo)]
-        #vis enum #inherent_hooks {
-            #(
-                #variants2(<#inner_types2 as tuxedo_core::ConstraintChecker<#verifier>>::InherentHooks),
-            )*
-        }
+        impl tuxedo_core::ConstraintChecker for #outer_type {
+            type Error = #error_type;
 
-        impl tuxedo_core::inherents::InherentInternal<#verifier, #outer_type> for #inherent_hooks {
+            fn check (
+                &self,
+                inputs: &[tuxedo_core::dynamic_typing::DynamicallyTypedData],
+                peeks: &[tuxedo_core::dynamic_typing::DynamicallyTypedData],
+                outputs: &[tuxedo_core::dynamic_typing::DynamicallyTypedData],
+            ) -> Result<TransactionPriority, Self::Error> {
+                match self {
+                    #(
+                        Self::#variants5(inner) => inner.check(inputs, peeks, outputs).map_err(|e| Self::Error::#variants5(e)),
+                    )*
+                }
+            }
+
+            fn is_inherent(&self) -> bool {
+                match self {
+                    #(
+                        Self::#variants2(inner) => inner.is_inherent(),
+                    )*
+                }
 
-            fn create_inherents(
+            }
+
+            fn create_inherents<V: tuxedo_core::Verifier>(
                 authoring_inherent_data: &InherentData,
-                previous_inherents: Vec<(tuxedo_core::types::Transaction<#verifier, #outer_type>, sp_core::H256)>,
-            ) -> Vec<tuxedo_core::types::Transaction<#verifier, #outer_type>>  {
+                previous_inherents: Vec<(tuxedo_core::types::Transaction<V, #outer_type>, sp_core::H256)>,
+            ) -> Vec<tuxedo_core::types::Transaction<V, #outer_type>>  {
 
                 let mut all_inherents = Vec::new();
 
@@ -272,7 +292,7 @@ pub fn tuxedo_constraint_checker(attrs: TokenStream, body: TokenStream) -> Token
                             })
                             .collect();
 
-                        let inherents = <#inner_types3 as tuxedo_core::ConstraintChecker<#verifier>>::InherentHooks::create_inherents(authoring_inherent_data, previous_inherents)
+                        let inherents = <#inner_types3 as tuxedo_core::ConstraintChecker>::create_inherents(authoring_inherent_data, previous_inherents)
                             .iter()
                             .map(|tx| tx.transform::<#outer_type>())
                             .collect::<Vec<_>>();
@@ -284,13 +304,13 @@ pub fn tuxedo_constraint_checker(attrs: TokenStream, body: TokenStream) -> Token
                 all_inherents
             }
 
-            fn check_inherents(
+            fn check_inherents<V: tuxedo_core::Verifier>(
                 importing_inherent_data: &sp_inherents::InherentData,
-                inherents: Vec<tuxedo_core::types::Transaction<#verifier, #outer_type>>,
+                inherents: Vec<tuxedo_core::types::Transaction<V, #outer_type>>,
                 result: &mut sp_inherents::CheckInherentsResult,
             ) {
                 #(
-                    let relevant_inherents: Vec<tuxedo_core::types::Transaction<#verifier, #inner_types4>> = inherents
+                    let relevant_inherents: Vec<tuxedo_core::types::Transaction<V, #inner_types4>> = inherents
                         .iter()
                         .filter_map(|tx| {
                             match tx.checker {
@@ -300,7 +320,7 @@ pub fn tuxedo_constraint_checker(attrs: TokenStream, body: TokenStream) -> Token
                         })
                         .collect();
 
-                    <#inner_types4 as tuxedo_core::ConstraintChecker<#verifier>>::InherentHooks::check_inherents(importing_inherent_data, relevant_inherents, result);
+                    <#inner_types4 as tuxedo_core::ConstraintChecker>::check_inherents(importing_inherent_data, relevant_inherents, result);
 
                     // According to https://paritytech.github.io/polkadot-sdk/master/sp_inherents/struct.CheckInherentsResult.html
                     // "When a fatal error occurs, all other errors are removed and the implementation needs to abort checking inherents."
@@ -311,12 +331,12 @@ pub fn tuxedo_constraint_checker(attrs: TokenStream, body: TokenStream) -> Token
             }
 
             #[cfg(feature = "std")]
-            fn genesis_transactions() -> Vec<tuxedo_core::types::Transaction<#verifier, #outer_type>> {
-                let mut all_transactions: Vec<tuxedo_core::types::Transaction<#verifier, #outer_type>> = Vec::new();
+            fn genesis_transactions<V: tuxedo_core::Verifier>() -> Vec<tuxedo_core::types::Transaction<V, #outer_type>> {
+                let mut all_transactions: Vec<tuxedo_core::types::Transaction<V, #outer_type>> = Vec::new();
 
                 #(
                     let transactions =
-                        <<#inner_types6 as tuxedo_core::ConstraintChecker<#verifier>>::InherentHooks as tuxedo_core::inherents::InherentInternal<#verifier, #inner_types6>>::genesis_transactions();
+                        <#inner_types2 as tuxedo_core::ConstraintChecker>::genesis_transactions();
                     all_transactions.extend(
                         transactions
                             .into_iter()
@@ -329,35 +349,6 @@ pub fn tuxedo_constraint_checker(attrs: TokenStream, body: TokenStream) -> Token
             }
 
         }
-
-        impl tuxedo_core::ConstraintChecker<#verifier> for #outer_type {
-            type Error = #error_type;
-
-            type InherentHooks = #inherent_hooks;
-
-            fn check (
-                &self,
-                inputs: &[tuxedo_core::types::Output<#verifier>],
-                peeks: &[tuxedo_core::types::Output<#verifier>],
-                outputs: &[tuxedo_core::types::Output<#verifier>],
-            ) -> Result<TransactionPriority, Self::Error> {
-                match self {
-                    #(
-                        Self::#variants5(inner) => inner.check(inputs, peeks, outputs).map_err(|e| Self::Error::#variants5(e)),
-                    )*
-                }
-            }
-
-            fn is_inherent(&self) -> bool {
-                match self {
-                    #(
-                        Self::#variants6(inner) => <#inner_types7 as tuxedo_core::ConstraintChecker<#verifier>>::is_inherent(inner),
-                    )*
-                }
-
-            }
-
-        }
     };
 
     output.into()